Commutator compound



Patented Sept. 25, 11923.

JEREMIAH E. FISHER, 015 NEW YORK, N. Y.

comm-neuron comroun'n. I

No Drawing To all whom it may concern Be it known that I, JEREMIAH E. FISHER, a citizen of the United States, and a resident of the borough of Manhattan, in the county of New York and State of New York, have invented a certain new and useful Commutator Compound, of which the following is a specification.

This invention relates generally to commutator compounds and particularly to a process method and compound for commutatOr lubrication.

This application is made pursuant to an order made December 28th, 1921, for division of applicants pending application for a commutator compound Serial No. 475,169, filed June 4th, 1921 modified by the oflice letter of May 29th, 1923, as being a continuation in part of said application.

In the present state of the art, no efiicient or satisfactory lubricant for a commutator has been found.

The function of such a lubricant includes Y not only the reduction of frictional wear commutator, besides greatly increasing the frictional loss through the grinding action of the brushes on the irregular contours, thus created, all of which in effect impairs the machine and reduces its efliciency; also torenew the brush faces and to maintain a polished surface thereon.

Carbon brushes havev practically displaced metallic ones on direct current machines while the latter are largely retained on alternating current machines.

Among other objects of my invention are the following: to prevent decomposition and scaling of the surface of a commutator, sparking, erosion, pitting, and striation of the commutator sections by electrolytic action and the consequent necessity of turning,

' rinding, or sandpapering such impaired suraces; also to protect the commutator surface with an oleaginous coating or skini and to prevent any electrolytic decomposltion of such surface.

Application filed January 10, 1922. Serial No. 528,255. 2

Other objects of my invention are to prevent the wear on the contact faces of the brushes, of electrical units; also to deposit, on the face of the carbon brushes, carbon adapted to produce apolished or glazed surface and thus to provide a dr lubricant on the contact surface of the brus and a liquid lubricant on the surface of the commutator.

These novel results and others, I obtain by my invention which includes a process method, and a compound comprising an oleaginous liquid hydrocarbon admixture having a chemical constitution'which commercially adapts it for the purposes aforesaid, and which requires application to the commutator surface only at infrequent intervals.

My compound is commercially adapted to form such a skin or coating on the commutator surface as shall render the latter immune from electrolytic decomposition, or sparking and to maintain such coating or skin by infrequent applications, and

thereby to prevent the deterioration of the commutator surface, as above described.

My compound is also commercially adapted to fill any inequalities which may exist on the contact surfaces of the commutator brushes by the electrolytic deposit of carbon thereon as for example, those produced by sand-papering carbon brushes, and to develop polished, or glazed faces upon such contact surfaces and to maintain the same and thereby preserve such brushes from the normal wear which they now undergo, thus extending their life indefinitely.

-By experiment I have discovered that by the use of a mixture of an oil having an asphalt base with one having a parafline content as hereinafter described and reducing the specific gravity of such mixture by the admixture therewith of kerosene as hereinafter described, I can obtain a product commercially adapted to secure the objects of my invention, and by further experiment I have discovered that by mixing oil having an asphalt content with kerosene, as hereinafter described I could also obtain a commercial product for my purposes, but not-as an oil having a parafiine content, or either of them or an admixture of either with kerosene only, are commercially adapted for the purposes mentioned herein.

In my compound an oil with an asphalt content is a necessary factor to promote the electrolysis required to provide a carbon deposit on the contact surfaces of the brushes, adapted to produce and constantly maintain a polished, or glazed, surface, and with its use the compound also forms a skin or coating on the commutator surface which can be maintained b infrequent applications of the compoun from eight to sixteen hours or more as may be desired. The addition of a parafline content is highly desirable to reduce frictional losses.

I will now more specifically describe my invention, including the compound which I use for said purposes nd how the same may be prepared, applied and used.

My invention includes a process method and a compound which latter I obtain preferably by an admixture the component parts of which are comprised of hydrocarbon compounds. In its preparation I preferably first mix an oil having an asphalt content with an oil having a parailine content, substantially in equal proportions, the oils being preferably of such respective Viscosity that the mixture shall have a related specific gravity of about .900 or .905. I then add suflicient kerosene to prevent danger of gumming on the commutator and for that purpose I preferably produce a mixture having a specific gravity of about .880.

-A less proportion of paraffiue oil may be used as desired, but it is not desirable to increase the proportion of kerosene as the latter tends to reduce the body of the mixture required to form the coating or skin, especially upon large electrical units. The specific gravity of the mixture may be reduced by the addition of more kerosene when desired. While I obtain the best results from the mixture above described, the same may be varied if desired by the reduction of the parafiine base content as stated, or its omission from the mixture, simply mixing an oil, having an asphalt content, with sufiicient kerosene to reduce its specific gravity so as to prevent gumming.

To the above mixture I preferably add a very small quantity oil of winter een or other essential 'oil to promote rapid difiusion of the other ingredientsof the mixture.

It is obvious that instead of a synthetic mixture of kerosene with a heavier oil of either a parafline or asphalt content an equivalent result might be obtained by selective distillation.

It is also obvious that the oils might be reduced inany suitable manner if desired, to a paste a semi-solid or solid form for convenient use.

aceaoee I have ascertained by experiment that my compound is equally adapted to prevent electrolysis of a commutator using metallic brushes and those having a metallic content. Also that it is adapted to revent electrolysis of the slip rings of a ternating current machines. The mixture is applied in a liquid state.

The operation of my compound is as follows:

Upon application of the mixture electrolytic action in decomposing the compound takes place immediately and is continuous until the electrolytic content of the compound is exhausted.

While this action continues, it is exerted exclusively in the decomposition of the compound, being diverted from the commutator and the commutator is thus protected and rendered entirely immune from such action.

When the compound is applied to the commutator of a D. G. electric unit decomposition of the element of the compound having an asphalt base, releases molecular carbon, in such proximity to the carbon brushes and in such a nascent state that the brushes act as nuclei. for the carbon particles resulting in the latter forming an integral union with the brush faces and pro viding a new polished surface on the brushes, which is continuously renewed reducing frictional wear of the contacting parts to a negligible quantity and preventing any frictional copper dust being disengaged.

The residue of the compound. after the electrolyte is decomposed remains on the surface of the commutator as a lubricating and protective skin or coating.

When the compound is applied to an A. C. electrical unit, the electrolytic action is diverted from the slip rings to the electrolytic component of the compound and the rings are similarly protected from electrolysis while the carbon particles remain suspended in the residue of the compound, thus providing an additional and valuable element of lubrication to prevent frictional wear on contacting parts.

The immediate efl'ect of a first application to an eroded and pitted commutator surface is to temporarily increase the sparking. Then, after a short time, all sparking and rattling or chattering characteristic of such a condition of the commutator A renewal of Il surface is being built up on the contact faces of the brushes.

Among other advantages from the use of my compound, are the building up of the skin or coating on the commutator thus preventing electrolytic action upon and deterioration of the commutator surface and obviating the need of resurfacing the commutator by turning, grinding, or sandpapering, as is now done, also by the automatic resurfacing of the carbon brushes to prevent the normal wearing down of their faces, also to provide dry lubrication and to reduce frictional Wearing of the commutator and brush surfaces. I have found this effect is directly related to the nature, composition and chemical constitution of the hydrocarbon compounds employed, the inclusion of a content having an asphalt base being essential as heretofore stated.

Having thus described my discovery and reserving for myself the right to make a1- sisting of an oil having an asphalt base, an-

oil having a paraffine base, kerosene, and sufiicient oil of Wintergreen to promote diffusion.

' 3. A spark preventing composition comprising in combination a mineral oil having an asphalt base admixed with a mineral oil having a parafline base, and kerosene to so reduce viscosity as to adapt the mixture for commutator lubrication.

Signed at New York in the county of New York and State of New York, this 7th day of January, 1922.

JEREMIAH E. FISHER. 

